The use of CAMEL (customized applications for mobile network enhanced logic) enables communication network operators, such as GSM or 3G network operators, to provide a wide range of enhanced services that are not provided for by the core communication network. CAMEL services are provided by appropriate service platforms, and enables network operators to provide subscribers with specific services both within, and when roaming outside, the home communication network.
If a functional entity of a mobile network, such as a visited MSC (VMSC), a gateway mobile switching center (GMSC) or a serving GPRS support node (SGSN), supports CAMEL functionality, the home location register (HLR) in the mobile network is configured with appropriate CAMEL subscriber information (CSI).
When a CAMEL subscriber attempts to register in an appropriate functional entity of a mobile network, such as in a VMSC or SGSN, the functional entity sends a registration request to the HLR. The registration request includes an identifier of the subscriber.
The HLR then retrieves a set of CAMEL subscriber information (CSI) for the particular set of CAMEL services to which the registering subscriber has access.